const 叫声映射 = new Map();
叫声映射.set('dog', 'woof');
叫声映射.set('cat', 'meow');
叫声映射.set('elepant', 'toot');
console.log(叫声映射.size);
console.log(叫声映射.get('dog'));
console.log(叫声映射.get('fox'));
console.log(叫声映射.has('bird'));
叫声映射.delete('dog');
console.log(叫声映射.has('dog'));

for (const [键, 值] of 叫声映射) {
    console.log(`${键} 的叫声: ${值}`);
}
叫声映射.clear();
console.log(叫声映射.size);
